The present disclosure relates generally to an ionizing radiation detector, and particularly to an ionizing radiation detector employing a backlit photodiode array.
Radiation imaging systems are widely used for medical and industrial purposes, such as for x-ray computed tomography (CT) for example. A typical detector system may comprise an array of scintillator elements attached to an array of photodiodes that are used to detect and convert ionizing radiation to light energy and then to electrical signals representative of the impinging ionizing radiation. To increase image quality, a large number of individual pixels is required, such as on the order of 1000 to 4000 individual pixels for example, with an amplifier being used for each respective pixel. As the number of individual pixels and amplifiers increases, providing the necessary signal connections for processing becomes complex and cumbersome. In an effort to resolve some of this complexity, backlit photodiode arrays have been investigated, which enables an increase in the number of photodiode detection elements in a photodiode array chip. However, backlit photodiode array chips are sensitive to electronic crosstalk, which results at least partially from the thickness of the photodiode array chip itself. Accordingly, there is a need in the art for an ionizing radiation detector arrangement that overcomes these drawbacks.